Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH v3 2/4] x86/microcode: Fix __user annotations around generic_load_microcode() | Date | Tue, 2 Apr 2019 10:26:30 +0000 |
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From: Borislav Petkov > Sent: 02 April 2019 11:02 > > On Mon, Apr 01, 2019 at 07:53:46PM +0200, Jann Horn wrote: > > Hm. request_microcode_fw() gets that buffer from > > request_firmware_direct(), which does this: > > > > __module_get(THIS_MODULE); > > ret = _request_firmware(firmware_p, name, device, NULL, 0, > > FW_OPT_UEVENT | FW_OPT_NO_WARN | > > FW_OPT_NOFALLBACK); > > module_put(THIS_MODULE); > > return ret; > > > > What is that module_get()/module_put() supposed to be good for? Are we > > expecting that caller to do something ridiculous like calling > > module_put() on us? This doesn't seem to make any sense. > > Yah, the microcode thing used to be a module. Not anymore.
That probably makes diddly-squit difference. There has to be a 'hold' on THIS_MODULE in order to be executing code from it. You only (usually) need an extra reference for a kernel thread, and that needs to exit with module_put_and_exit().
David
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